1. Field of the Invention
The present invention generally relates to a fluxgate sensor. More particularly, the present invention relates to a fluxgate sensor integrated in a semiconductor substrate and a method for manufacturing the same.
2. Description of the Related Art
The existence of magnetic energy has been proven through various physical phenomena. For example, a fluxgate sensor enables a human to indirectly perceive magnetic energy since magnetic energy is not perceivable by human sense organs, such as eyes or ears. Regarding a fluxgate sensor, a magnetic sensor employing a soft magnetic body and coil have been conventionally used. A magnetic sensor is made by winding a coil around a relatively large bar-shaped core or annular-shaped core, which is formed of a soft magnetic ribbon. In addition, an electronic circuit is employed to obtain a magnetic field in proportion to the measured magnetic field.
The conventional fluxgate sensor, however, has the following problems, some of which are due to the structure of the conventional fluxgate sensor. In the structure of a conventional fluxgate sensor, the coil being wound around a large bar-shaped core or annular-shaped core, which is made of soft magnetic ribbon, results in high production costs and a large overall size of the system. In addition, magnetic flux leakage by the core is inevitable in the flux change generated by an excitation coil. Accordingly, high sensitivity is not readily achieved.